If Telecommunication is Such a
Good Substitute for Travel,
Why Does Congestion Continue
to Get Worse?
Patricia L. Mokhtarian
University of California, Davis
Dept. of Civil & Environmental Engineering
and Institute of Transportation Studies
plmokhtarian@ucdavis.edu
www.its.ucdavis.edu/telecom
A simple premise

We’ve been telecommunicating for an awfully
long time now… by sound…
Premise (cont’d)

and sight…
Introduction (cont’d)

The written word…
Introduction (cont’d)

Electronic communication…
Introduction (cont’d)
Saving travel has been at least one
motivation from the beginning
 Made explicit from the late 1800s

– 1879 London Spectator and The Times
– 1899, H. G. Wells, “When the Sleeper Wakes”
» The “kineto-tele-photograph” = videoconferencing
– 1909, E. M. Forster, “The Machine Stops”

Subject of scholarly study (congestion
reduction perspective) since 1960s
Introduction (cont’d)
So since information/communication technology
(ICT) usage looks like this…

Telecommunications Trends (1950 = 100)
6000
5000
Local phone calls, Y1
Toll phone calls, Y1
International phone calls, Y2
Cellular phone subscribers, Y2
1000000
900000
800000
700000
4000
3000
500000
400000
2000
300000
200000
1000
100000
0
0
1950 1952 1954 1956 1958 1960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000
Y2
Y1
600000
Introduction (cont’d)

Then surely traffic congestion must have
almost disappeared by now?
Introduction (cont’d)

But wait – then why does it look like this??
Transportation Trends (1950 = 100)
700
600
VMT (cars), Y1
Transit passengers, Y1
Airline domestic PMT, Y2
Airline international PMT, Y2
9000
8000
7000
500
5000
300
4000
Y1
400
3000
200
2000
100
1000
0
0
1950 1952 1954 1956 1958 1960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000
Y2
6000
Introduction (cont’d)

And this?!
Introduction (cont’d)

And this?
Source: Schrank & Lomax (2007)
The purposes of this talk are…

To explain this apparent paradox:
– 5 reasons why ICT doesn’t decrease travel
– 7 reasons why it actively increases it
To discuss reasons for optimism that ICT
can reduce travel (only 4…)
 To (briefly) explore policy implications

Activities
5 reasons why ICT does not reduce travel
no ICT counterpart
1. Not all activities have an
ICT counterpart
5 reasons why ICT does not reduce travel
1. Not all activities have an
ICT counterpart

Co-location of people is needed to
– perform surgery
– cut hair
– care for children

Humans must be in specific locations to
– garden, clean house
– repair vehicles
– fix plumbing

We need material objects, not digital files, for
– food, clothing, shelter, & amenities
5 reasons why ICT does not reduce travel
ICT not feasible
no ICT counterpart
2. ICT is not always a
feasible alternative
5 reasons why ICT does not reduce travel
2. ICT is not always a
feasible alternative
Infrastructure not ubiquitous
 Even if infrastructure present, the requisite
service may not be available
 Even if service available, it may not be
activated for the event in question

5 reasons why ICT does not reduce travel
ICT not desirable
ICT not feasible
no ICT counterpart
3. ICT is not always a
desirable substitute
5 reasons why ICT does not reduce travel
3. ICT is not always a
desirable substitute


Location amenities
Co-presence with other people (& objects!)
– Need for touch
– Richer communication, relationship development
possibilities





Side trip, trip chaining possibilities
Welcome departure from routine
Escape from pressures “back home”
Signal of status
Preference for authenticity over virtuality
5 reasons why ICT does not reduce travel
4. Travel carries (some)
positive utility










Curiosity, variety-, adventure-seeking
Exposure to the environment, information-gathering
Enjoyment of a route, not just a destination
Pride in skillful control of movement
Conquest
Sensation of speed or even just movement
Symbolic value (status, independence)
Escape, buffer
Physical/mental therapy
Synergy
5 reasons why ICT does not reduce travel
4. (cont’d)
As the psychologists would say, some travel
is “autotelic” – undertaken for its own sake
(auto = self; telos = goal or purpose)
 Many characteristics of undirected travel
that contribute to its positive utility apply to
more directed travel as well (to degrees
differing by person and circumstance)

5 reasons why ICT does not reduce travel
4. (cont’d)

Resulting in
– Trips that don’t have to be made (e.g.
commuting instead of telecommuting)
– and, for trips that do have to be made:
» Destinations that are farther than “necessary”
» A preference for travel modes offering
independence, status, speed, etc.
» Routes that are longer than necessary (for scenery,
variety, companionship, etc.)
replaced by ICT
ICT not desirable
ICT not feasible
no ICT counterpart
5 reasons why ICT does not reduce travel
replaced by ICT
ICT not desirable
ICT not feasible
no ICT counterpart
5. Not all ICT uses
replace travel
ICT
activities
that don’t
replace
travel
5 reasons why ICT does not reduce travel
5. Not all ICT uses
replace travel

The alternative may not be
– traveling to the activity
but rather
– not conducting the activity at all

Consider
– distance learning
– internet shopping
– e-mail
5 reasons why ICT does not reduce travel
5. (cont’d)



The travel share of the
communications pie
may be decreasing
but the whole pie is
expanding so much, that
in absolute terms, travel
is still increasing
electronic
transmission information
freight
personal
travel
7 reasons why ICT actively increases travel
6. ICT saves time in general
Some of the time saved (e.g. by telecommuting) could be spent on other activities,
possibly involving travel
 Empirically, does not appear to be a strong
effect
 But could generate some travel at the
margin

7 reasons why ICT actively increases travel
7. ICT permits travel
to be sold more cheaply
Price comparisons
 Price alerts
 Last-minute bargains
 Possible effects:

– Can save money on a given trip – savings may be
partly spent on more travel
– May substitute a longer trip for the same budget
– May stimulate entirely new trips – more
affordable to more people
7 reasons why ICT actively increases travel
8. ICT increases the efficiency
of the transportation system
Lowering the time and/or monetary cost of
travel increases the demand for it
 Applications:

–
–
–
–
Intelligent Transportation Systems
Electronic Data Interchange
Global Positioning System
Radio Frequency Identification
7 reasons why ICT actively increases travel
9. ICT increases productivity/
enjoyment of travel time

ICT-enabled activities while traveling:
– Talking on the phone
– Working on a standalone laptop
– Surfing the web
Reduce the motivation to save travel time
 At the margin, may actively increase it

– Choose a longer transit commute over auto
7 reasons why ICT actively increases travel
9. (cont’d)

ICT-enabled activities while traveling:
– Talking on the phone
– Working on a standalone laptop
– Surfing the web
Reduce the motivation to save travel time
 At the margin, may actively increase it

– Choose a longer transit commute over auto
– Can make more business trips
7 reasons why ICT actively increases travel
10. ICT directly stimulates
additional travel

Message content may directly invite travel
– “Mr. Watson, come here – I want to see you”
– Use of mobile phone to schedule meetings

Increasing accessibility increases engagement
in activities that collaterally involve travel
7 reasons why ICT actively increases travel
10. (cont’d)

Message content may directly invite travel
– “Mr. Watson, come here – I want to see you”
– Use of mobile phone to schedule meetings
Increasing accessibility increases engagement
in activities that collaterally involve travel
 ICT fosters expectation of instant gratification

7 reasons why ICT actively increases travel
11. ICT drives increasing
globalization of commerce

Lowered information & transaction costs
– directly stimulate business
– release resources for alternative uses
Leads to growing (broader and deeper)
customer base
 Facilitates greater geographic separation of
functions, thereby
 Requiring more movement of goods & people

7 reasons why ICT actively increases travel
12. ICT facilitates shifts to more
decentralized, lower-density
land use patterns
It also facilitates centralization/densification
 Technology is neutral; we have a personal and
collective choice in how it is applied

7 reasons why ICT actively increases travel
12. ICT facilitates shifts to more
decentralized, lower-density
land use patterns
It also facilitates centralization/densification
 Technology is neutral; we have a personal and
collective choice in how it is applied
 Decentralization has many “causes”, and
trends predate internet and other modern ICTs
 The news for telecommuting, however, is
largely good

So… is there any hope for
ICT to reduce travel?

Some…
4 reasons for hope
1. Sometimes ICT does
substitute for making a trip
Telecommuting appears to be a net benefit
 Insignificant effects in some models may be
substitution and complementarity canceling
 Substitution effects might, in fact, be
substantial (even if often more-thancounteracted by generation effects)

2. ICT consumes time/money


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ICT takes time as well as making time
Some studies have found a “displacement” effect –
more time on the internet associated with less time
on out-of-home activities and travel
(But a number of others have found
complementarity between ICT use and out-ofhome activities/travel)
4 reasons for hope
3. If travel costs increased
dramatically…

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Previous research assumes “business as usual”
Extreme events affecting work locations or
transportation network stimulate substitution of
ICT for travel, at least temporarily
Travel pricing policies or trends (congestion
pricing, fuel tax/price, carbon tax, market-priced
parking, etc.) could stimulate demand for ICT
substitutes
(But gasoline consumption appears to be rather
price-insensitive – travel is still an attractive/
compelling alternative in many cases)
4 reasons for hope
4. ICT can make shared
travel modes more attractive
Enables pre-trip, en-route information about
public transit
 Enables real-time ridesharing, carsharing
 Decreases the disutility of travel by making
travel time more productive/enjoyable – the
more so for “hands-free” shared modes

The challenge
The same technological advances that make
ICT an attractive substitute for travel also
create synergies with travel
 The same ICT-based mechanisms that make
public transit more attractive can also make
driving more attractive

The challenge
The same technological advances that make
ICT an attractive substitute for travel also
create synergies with travel
 The same ICT-based mechanisms that make
public transit more attractive can also make
driving more attractive
 Thus, ICT is inextricably part of the
“problem” as well as the “solution”

Speaking of a dual nature…

Travel itself is a two-sided phenomenon:
– Yes, we need to try to mitigate its negative
externalities
– But, mobility has personal, social, economic
benefits, and we will pay a societal price when
we curtail it
Perhaps we can agree…
Providing attractive alternatives to travel is
a good thing, and
 so is using the transportation system more
efficiently, so that more travel can be
accommodated within the existing network
 ICT has a clear role to play in both of these
strategies, and thus
 merits public policy support

For further reading
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Albertson, L. A. (1977) “Telecommunications as a travel substitute: Some psychological, organizational, and social aspects”. Journal of Communication 27(2), 32-43.
Albertson, L. A. (1980) “Trying To Eat an Elephant”, review essay on The Social
Psychology of Telecommunications, by John Short, Ederyn Williams, and Bruce Christie
(London: John Wiley, 1976) Communication Research 7(3), 387-400.
Choo, S. & P. L. Mokhtarian (2007) “Telecommunications and Travel Demand and
Supply: Aggregate Structural Equation Models for the U.S.” Transportation Research
A 41(1), 4-18.
Choo, S., T. Lee, & P. L. Mokhtarian (2007) “Relationships between U. S. Consumer
Expenditures on Communications and Transportation Using Almost Ideal Demand
System Modeling: 1984-2002”. Transportation Planning and Technology 30(5), 431453.
Choo, S., P. L. Mokhtarian, and I. Salomon (2005) “Does Telecommuting Reduce
Vehicle-miles Traveled? An Aggregate Time Series Analysis for the U.S.”.
Transportation 32(1), 37-64.
Hughes, J.E., C. R. Knittel & D. Sperling (2006) “Evidence of a Shift in the ShortRun Price Elasticity of Gasoline Demand”. Working paper UCD-ITS-RR-06-16,
http://pubs.its.ucdavis.edu/publication_detail.php?id=1050.
Lee, T. & P. L. Mokhtarian (2008) “Correlations between Industrial Demands (Direct
and Total) for Communications and Transportation in the U.S. Economy, 1947-1997”.
Transportation 35(1), 1-22.
For further reading (cont’d)
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Mokhtarian, P. L. (1990) “A Typology of Relationships between Telecommunications
and Transportation”. Transportation Research A 24A(3), 231-242.
Mokhtarian, P. L. (1998) “A Synthetic Approach to Estimating the Impacts of
Telecommuting on Travel”. Urban Studies 35(2), 215-241.
Mokhtarian, P. L. (2004) “A Conceptual Analysis of the Transportation Impacts of B2C
E-Commerce”. Transportation 31(3), 257-284.
Mokhtarian, P. L. (2003) “Telecommunications and Travel: The Case for Complementarity”. Journal of Industrial Ecology 6(2), 43-57. mitpress.mit.edu/jie/e-commerce
Mokhtarian, P. L. & I. Salomon (2001) “How derived is the demand for travel? Some
conceptual and measurement considerations.” Transportation Research A 35, 695-719.
Mokhtarian, P. L., I. Salomon, & S. L. Handy (2006) “The Impacts of ICT on Leisure
Activities and Travel: A Conceptual Exploration”. Transportation 33(3), 263-289.
Ory, D. T. & P. L. Mokhtarian (2006) “Which Came First, the Telecommuting or the
Residential/Job Relocation? An Empirical Analysis of Causality”. Urban Geography
27(7), 590-609.
Owen, W. (1962) “Transportation and technology”. The American Economic Review
52(2), 405-413.
Schrank, D. & T. Lomax (2007) The 2007 Urban Mobility Report. Texas Transportation Institute, September. http://tti.tamu.edu/documents/mobility_report_2007.pdf
Transportation Research A 39(2&3), special issue on the Positive Utility of Travel.
Questions?
plmokhtarian@ucdavis.edu
www.its.ucdavis.edu/telecom/
Slide borrowed from David Ory